package indi.free.widgets.custom_fragment;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;

import java.util.List;

public class FragmentTabAdapter {
    // 一个tab页面对应一个Fragment
    private List<Fragment> fragments;

    // 用于切换tab
    private RadioGroup rgs;


    private FragmentActivity fragmentActivity;

    // 容器id
    private int fragmentContentId;

    // 当前Tab页面索引
    private int currentTab;

    // 用于让调用者在切换tab时候增加新的功能
    private OnRgsExtraCheckedChangedListener onRgsExtraCheckedChangedListener;

    /**
     * 构造函数
     *
     * @param mainFragment
     * @param fragments
     * @param fragmentContentId
     * @param rgs
     */
    public FragmentTabAdapter(FragmentActivity fragmentActivity, List<Fragment> fragments, int fragmentContentId, RadioGroup rgs) {

        this.fragmentActivity = fragmentActivity;
        this.fragments = fragments;
        this.rgs = rgs;
        this.fragmentContentId = fragmentContentId;


        // 默认显示第一页
        FragmentTransaction ft = fragmentActivity.getSupportFragmentManager()
                .beginTransaction();
        ft.add(fragmentContentId, fragments.get(0));
        ft.commit();
        // 设置监听事件
        MyCheckedChangeListener myCheckedChangeListener = new MyCheckedChangeListener();
        rgs.setOnCheckedChangeListener(myCheckedChangeListener);
    }

    /**
     * 监听器内部类
     *
     * @author
     */
    class MyCheckedChangeListener implements OnCheckedChangeListener {

        @Override
        public void onCheckedChanged(RadioGroup group, int checkedId) {
            for (int i = 0; i < rgs.getChildCount(); i++) {
                if (rgs.getChildAt(i).getId() == checkedId) {
                    Fragment fragment = fragments.get(i);
                    FragmentTransaction ft = obtainFragmentTransaction(i);

                    getCurrentFragment().onPause(); // 暂停当前tab
                    // getCurrentFragment().onStop(); // 暂停当前tab

                    if (fragment.isAdded()) {
                        // fragment.onStart(); // 启动目标tab的onStart()
                        fragment.onResume(); // 启动目标tab的onResume()
                    } else {
                        ft.add(fragmentContentId, fragment);
                    }
                    showTab(i); // 显示目标tab
                    ft.commit();

                    // 如果设置了切换tab额外功能功能接口
                    if (null != onRgsExtraCheckedChangedListener) {
                        onRgsExtraCheckedChangedListener
                                .OnRgsExtraCheckedChanged(group, checkedId, i);
                    }
                }
            }
        }
    }

    /**
     * 切换tab
     *
     * @param idx
     */
    private void showTab(int idx) {
        for (int i = 0; i < fragments.size(); i++) {
            Fragment fragment = fragments.get(i);
            FragmentTransaction ft = obtainFragmentTransaction(idx);

            if (idx == i) {
                ft.show(fragment);
            } else {
                ft.hide(fragment);
            }
            ft.commit();
        }
        currentTab = idx; // 更新目标tab为当前tab
    }

    /**
     * 获取一个带动画的FragmentTransaction
     *
     * @param index
     * @return
     */
    private FragmentTransaction obtainFragmentTransaction(int index) {
        FragmentTransaction ft = fragmentActivity.getSupportFragmentManager()
                .beginTransaction();
        // 设置切换动画
     /*   if (index > currentTab) {
            
            ft.setCustomAnimations(android.R.animator.fade_in);
        } else {
            ft.setCustomAnimations(R.anim.slide_in_left, R.anim.slide_out_right);
        }*/
        return ft;
    }

    public int getCurrentTab() {
        return currentTab;
    }

    public Fragment getCurrentFragment() {
        return fragments.get(currentTab);
    }

    public OnRgsExtraCheckedChangedListener getOnRgsExtraCheckedChangedListener() {
        return onRgsExtraCheckedChangedListener;
    }

    public void setOnRgsExtraCheckedChangedListener(
            OnRgsExtraCheckedChangedListener onRgsExtraCheckedChangedListener) {
        this.onRgsExtraCheckedChangedListener = onRgsExtraCheckedChangedListener;
    }

    /**
     * 切换tab额外功能功能接口
     */
    static class OnRgsExtraCheckedChangedListener {
        public void OnRgsExtraCheckedChanged(RadioGroup radioGroup,
                                             int checkedId, int index) {
        }
    }
}